Tire construction



on fabric that previously has been coated with the rubber of highsulphur content. On the chafer strips I6 the coating of rubbercontaining accelerators will be disposed between the two strips.

Aside from the use of rubber composition of high sulphur content in thebead regions of the tire as described, the tire is of usual constructionand is vulcanized in the usual or any suitable manner. The rubber ofhigh sulphur content is somewhat stiller after vulcanization thanordinary rubber,

composition. and since but a small percentage of sulphur is required toeffect vulcanization it willl be obvious that there will be arelatively' large `v amount of free, uncombined sulphur in the beadregions of the ilnished tire, although somevof this sulphur willmigratev to adjacentregions during vulcanization. Under the extreme heatconditions incidental to use, the free sulphur further migrates andcauses a further stiffening of the rubber in the bead regions of thetire, and ,effec-y .tively prevents the softening of the rubber due toreversion. l

Although the sulphur content stated V(56% of. the amount of the rubber)has been found to give optimum results -the proportion of sulphur may bereduced without sacrificing all of the advantages `oi' the. invention.Experience has shown that reducing the proportion of sulphur from theamount stated reduces the protection against bead failure in a more orless proportionate degree.'

Used in lb us andf truckI tires subject to extreme heat conditions Yat.the beads, the invention prolongs the life 'of the tire, practicallyeliminates bead separation failures, and achieves the other Y 1. A tireconstruction consisting of a pneumatic* objects set out in' theforegoing statement of` objects.

Modmcauon may be resorted to without depart# ing from the spirit of theinvention or the scope of the appended claims, which are not limitedwholly to the specific construction lshown and ,de-r

scribed.

What is claimed is:

tire casing having an excessive amount of free sulphur in the beadregions thereof as compared to 'other parts of the tire.

2. A tire construction consisting of a pneumatic tirecasing having anexcess of free sulphur in the ybead regionsl thereof sufilcient toinhibit depolymerization ofthe rubber'under conditions of extreme heat.

3. A vulcanized tire construction consisting of a pneumatictire casinghaving localized plies in the bead regions thereof, which plies containrubber of excessive combinable sulphur content as compared to the otherplies of said bead region.

region thereof, which ply contains rubber composition of which thesulphur content is substan-f tially the maximum amount thatcanbeincorporated in the composition. 4

6. A tire construction as deilned in claim 5 in which the sulphurcontent of the rubber composition of the localized plies issubstantially 50% ofthe weight of therubbe'r in said plies. y

7. vAvvuicanized tire construction consisting of a pneumatic tire casingvhaving respective bead reinforcing plies comprisingl rubber ofexcessive combinable sulphur content as compared to the other carcassplies of the tire. v

8. A tire construction as defined in claim, 7 including chafer stripscomprising rubber of the same high sulphurcontent as the bead reinforc.ing plies.

RAYMOND lS.`TAYLOR..

